systemd is like the service manager for your Centos and other modern Linux distributions (including Debian/Mint/Ubuntu) allows you to enable services, stop them, restart them, check their status and even reboot your system.
The key commands or arguments you will use with systemctl are the following:
list-units [PATTERN...] List loaded units
zenity is a nice utility as part of the gnome window manager that allows you to script from bash and retrieve the input from the user. It could also be helpful in just notifying a user when they login with a popup window.
I'll give an overview of what's available with zenity:
--calendar Display calendar dialog
--entry Display tex........
This happens because Dovecot limits the maximum IMAP connections per IP to just 10. This may be fine for a single client side IP but if an entire office or multiple users are behind one IP or a single heavy user is active then you will get bizarre errors in your e-mail clients such as "Password Incorrect" or similar in Thunderbird. It won't be obvious on the client side as to what the problem is and they will probably just think the server is misconfi........
**** Warning: can't process font stream, loading font by the name.
Can't find CMap Identity-UTF16-H building a CIDDecoding resource.
Warning: falling back to Identity ordering
**** Error reading a content stream. The page may be incomplete.
**** File did not complete the page properly and may be damaged.
**** This file had errors that were repaired or ignored.
I keep reading these drives are slower, but they are cheap and still SSD and work very fast for my needs.
As you can see the sequential read is 481-491MB/s, if I put them in MDADM RAID10 mode (normal RAID1) they should give me well over 900MB/s and with redundancy and being very cheap for what they offer.
[1232206.315622] scsi 8:0:1:0: Direct-Access ATA ADATA SU800 &........
This happened while an mdadm array was syncing, all access from writing a new blank file to opening a small .txt file was very slow:
[222117.312078] kjournald starting. Commit interval 5 seconds
[222117.685060] EXT3-fs (md0): using internal journal
[222117.685096] EXT3-fs (md0): mounted filesystem with ordered data mode
[222122.376847] kjournald starting. Commit interval 5 seconds
[222122.602825] EXT3-fs (md2): using internal jour........
What does VPN stand for?
VPN stands for Virtual Private Network and is a secure way of connecting networks and devices.
In the context we're talking about it will usually be a client-server solution and not connecting whole networks or businesses.
The assumption is that most people reading this are trying to secure their internet connection, privacy and hide or change their IP address.
Why use a VPN?
There are many........
I had a system running a 128MB live CD image with 2.8 gigs of available RAM and the OOM kernel killer went crazy when using dd for more than 8 minutes and kept killing everything. I've read that this is due to a low-memory issue and paging in the kernel and 32-bit systems with lots of RAM.
I even enabled swapspace on my LiveCD and the issue happened 25 minutes into dd rather than 8 minutes, so what gives?
Also no swap space was ever used!
When trying to even cd or ls the mounted OCFS2 partition it crashes. I think this is a combination of VMWare Server's problem and the way I mounted and symlinked to it.
More than anything this shows the problem and lack of forsight with VMWare, but also that OCFS2 is easily crashed if you do strange things.
Output of /var/log/messages for OCFS2
Apr 10 15:57:45 localhost kernel: [84331.691258] Modules linked in: vmnet vmci vmmon ocfs2_stac........